This application claims the benefit of a Japanese Patent Application No. 2000-145696 filed May 17, 2000, in the Japanese Patent Office, the disclosure of which is hereby incorporated by reference.
1. Field of the Invention
The present invention generally relates to information recording media and information processing apparatuses, and more particularly to an information recording medium which is printed with various information in advance, such as plain paper and predetermined paper having an image display layer for rewritably displaying various information using thermochromic or the like, and to an information processing apparatus which displays and processes various information using such an information recording medium.
2. Description of the Related Art
Recently, there is active research and development related to this type of information processing apparatus, and various proposals have been made. For example, an information processing apparatus was proposed in a Japanese Laid-Open Patent Application No. 9-101864. As a technique for storing various information such as characters and images in a visual state, the proposed information processing apparatus utilizes the advantages of conventionally used plain paper and a computer which is made up of a display and a memory.
FIGS. 1 and 2 respectively are a perspective view and a side view showing a structure of this proposed information processing apparatus. The information processing apparatus includes a digitizer (tablet) 101 which is used in combination with a plurality of digital papers 100. Each digital paper 100 uses color thermochromic in an image display layer, and forms an information recording medium (or information display medium) in a generally paper form for rewritably displaying various information. The color thermochromic which forms the image display layer of the digital paper 100 is obtained by mixing a leuco dye and a developer. The color thermochromic is adjusted so as to undergo a reversible change between a transparent state and a black state depending on heating. In a transparent portion of the image display layer, a white base film is visible through the image display layer and a transparent protection film. On the other hand, in a portion of the image display layer which changed to black, this black portion is visible through the transparent protection film. For this reason, an image display surface 102 is formed on the entire surface region of the digital paper 100, and this image display surface 102 rewritably displays the various information. Since the image display on the image display surface 102 is realized by the change in state of the image display layer, energy is required to display and erase the image information, but no energy is required to maintain the displayed image information.
As shown in FIG. 1, the digitizer 101 includes a plate-shaped main body board 103, and a heat panel 104 is provided on the surface of this main body board 103. The heat panel 104 includes a plurality of heating elements (not shown) which are arranged vertically and horizontally in an array at a density of 400 dots per inch (dpi), for example, which is larger than A4 size. A transparent input film 105 is provided on one end of the main body board 103 in a manner free to open and close, and this input film 105 is positioned on the surface of the heat panel 104. A writing pen 106 is used to write the various information on the digital paper 100.
In other words, according to the proposed information processing apparatus, the various information created by the computer or input by handwriting can be rewritably written on the digital paper 100, without wasting paper. In addition, the various information can be treated as digital information which is stored in a memory, externally output, externally input or processed in the computer.
However, from the point of view of usability, in the case of a working process which additionally writes to the document on a plurality of digital papers 100 which are already written or printed with the various information and are stacked, the information processing apparatus shown in FIGS. 1 and 2 requires one digital paper 100 (one page) to be placed on the digitizer 101 to make the additional writing and/or input and output of information, the one digital paper 100 (one page) to be removed after the additional writing and another digital paper 100 (another page) to be placed on the digitizer 101 to make the additional writing and/or input and output of information. As a result, the additional writing requires an extremely troublesome operation when carrying out such a working process which is often encountered in when holding a conference, performing a document checking, performing creative activities and the like.
In addition, the proposed information processing apparatus uses a method of storing contents on the digital paper 100, both before and after the additional writing, into an information storage medium such as a memory chip. However, this method is not suited for an operation or work which requires the plurality of stacked digital papers 100 to be used as if turning the pages, because it is impossible to relate or link the information on the digital papers 100 before the additional writing, the information on the digital papers 100 after the additional writing, and the pages of the digital papers 100 where the additional writing was made. In other words, no means is provided to identify each of the digital papers 100 stacked on the digitizer 101.
On the other hand, a method of identifying the information recording medium loaded on the tablet is proposed in a Japanese Laid-Open Patent Application No. 7-200134, for example. According to this proposed method, identification information such as a bar code is printed in a top peripheral portion of each information recording medium, and a detecting means for detecting the identification information is provided in a clip part which is provided at the top end of the tablet for holding the information recording medium. But from the practical point of view, only one information recording medium can be loaded on the tablet. Otherwise, if a plurality of information recording media were stacked on the tablet and the writing were made with respect to an arbitrary information recording medium by turning the information recording media, the detecting means would only be able to detect the identification information of the information recording medium located at the top of the stack, and it would be impossible to detect the identification information of the arbitrary information recording medium which is located at a position other than the top of the stack.
FIGS. 3 and 4 respectively are a perspective view and a side view of the information processing apparatus employing this proposed method. As shown in FIGS. 3 and 4, there are many situations where one of stacked information recording media 113 is turned halfway to write on a next information recording medium 113. But since a bar code 110 is printed in the top peripheral portion of each information recording medium 113 and the stacked information recording media 113 are held by a clip part 112 which is provided with a two-dimensional bar code reader 111, it is only possible to recognize the bar code 110 of the top information recording medium 113 even when the top information recording medium 113 is turned to write on the next information recording medium 113 which is located under the top information recording medium 113.
Therefore, the problems of the prior art can be summarized by (1) through (3), as follows.
(1) The Japanese Laid-Open Patent Application No. 9-101864 proposes an information recording apparatus which reads written information as electronic data, an information storage medium which stores the electronic data, and an information processing apparatus which includes an information recording medium for displaying the electronic data. In the information processing apparatus, the electronic data read from the information storage medium by the information recording apparatus are also displayed on the information recording medium. In addition, the information displayed on the information recording medium can be freely erased or corrected. Accordingly, the above information processing apparatus can create and store documents without wasting paper.
The information processing apparatus is designed to employ advantages of both a computer which includes a display and a memory, and paper which is conventionally used as a means for displaying various kinds of information such as characters and images for a predetermined time, based on analysis results of the advantages and disadvantages of the computer and the paper. In other words, the information which is created by the computer or input by handwriting is rewritable a plurality of times with respect to the information recording medium which is used by the information processing apparatus, and it is possible to avoid wasting the information recording medium as in the case of paper. In addition, the information processing apparatus can store the information or exchange the information with an external apparatus, as digital information which can be processed in the computer.
However, in the above information processing apparatus, document processes such as additional writing and storage must be carried out one information recording medium at a time, even when the additional writing is to be made with respect to a plurality of information recording media which are already written or printed with information, thereby making it troublesome to use the information processing apparatus.
In addition, when successively carrying out the additional writing with respect to a plurality of pages while turning over the plurality of information recording media, for example, there is a problem in that it is impossible to identify the page with respect to which the information was input, that is, the additional writing was made.
(2) On the other hand, the Japanese Laid-Open Patent Application No. 7-200134 proposes an information processing apparatus for inputting, storing and transferring data, and having a clip which holds the medium and is provided with a bar code reader for detecting identification (ID) information, in order to identify each medium placed on a board of the information processing apparatus.
But the bar code reader detects a bar code which is printed on the medium, from above the medium. Hence, when actually using the bar code reader, the media must be placed on the board one medium at a time. In other words, since a part of the medium printed with the bar code is held by the clip, there is a problem in that the bar code which is detected by the bar code reader provided in the clip remains unchanged even in a case where a plurality of media are placed on the board and one or more media are turned over, for example. Furthermore, although the Japanese Laid-Open Patent Application No. 7-200134 proposes the detection and use of the identification information, no mention is made with regard to security.
(3) On the other hand, another information processing apparatus has been proposed which uses rewritable paper made of a reversible recording material, when inputting electronic data from written information. The demand for the rewritable paper is increasing recently, from the point of view of solving environmental problems.
However, there is a problem in that an erroneous erasure or rewriting with respect to the rewritable paper may be made by the user himself or by a third party.